/**
 * Base CSS - Design System
 * Green Energy Career Night V4
 */

/* ===================================
   Custom Fonts
   =================================== */
@font-face {
    font-family: 'Alpha Lyrae';
    src: url('../fonts/AlphaLyrae-Medium.woff2') format('woff2'),
         url('../fonts/AlphaLyrae-Medium.woff') format('woff'),
         url('../fonts/AlphaLyrae-Medium.otf') format('opentype');
    font-weight: 500;
    font-style: normal;
    font-display: swap;
}

/* ===================================
   CSS Custom Properties (Variables)
   =================================== */
:root {
    /* Primary Greens - Teal-leaning, warmer */
    --color-primary: #2D6A4F;
    --color-primary-light: #40916C;
    --color-primary-dark: #1B4332;
    --color-primary-pale: #D8F3DC;

    /* Accent - Warm Amber/Gold */
    --color-accent: #E09F3E;
    --color-accent-light: #F4C95D;
    --color-accent-pale: #FEF3D0;

    /* Human Warmth Colors */
    --color-warmth: #E07A5F;
    --color-energy: #F2CC8F;

    /* Neutrals */
    --color-white: #FFFFFF;
    --color-black: #1A1A1A;
    --color-gray-50: #FAFAFA;
    --color-gray-100: #F5F5F5;
    --color-gray-200: #E5E5E5;
    --color-gray-300: #D4D4D4;
    --color-gray-400: #A3A3A3;
    --color-gray-500: #737373;
    --color-gray-600: #525252;
    --color-gray-700: #404040;
    --color-gray-800: #262626;
    --color-gray-900: #171717;

    /* Typography */
    --font-display: 'Alpha Lyrae', 'Inter', sans-serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

    /* Font Sizes - Fluid Scale */
    --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
    --text-sm: clamp(0.875rem, 0.8rem + 0.375vw, 1rem);
    --text-base: clamp(1rem, 0.925rem + 0.375vw, 1.125rem);
    --text-lg: clamp(1.125rem, 1rem + 0.625vw, 1.375rem);
    --text-xl: clamp(1.25rem, 1.1rem + 0.75vw, 1.625rem);
    --text-2xl: clamp(1.5rem, 1.25rem + 1.25vw, 2rem);
    --text-3xl: clamp(1.875rem, 1.5rem + 1.875vw, 2.5rem);
    --text-4xl: clamp(2.25rem, 1.75rem + 2.5vw, 3.25rem);
    --text-5xl: clamp(3rem, 2.25rem + 3.75vw, 4.5rem);
    --text-6xl: clamp(3.75rem, 2.75rem + 5vw, 6rem);

    /* Font Weights */
    --font-light: 300;
    --font-normal: 400;
    --font-medium: 500;
    --font-semibold: 600;
    --font-bold: 700;

    /* Line Heights */
    --leading-none: 1;
    --leading-tight: 1.25;
    --leading-snug: 1.375;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;
    --leading-loose: 2;

    /* Letter Spacing */
    --tracking-tighter: -0.05em;
    --tracking-tight: -0.025em;
    --tracking-normal: 0;
    --tracking-wide: 0.025em;
    --tracking-wider: 0.05em;

    /* Spacing Scale */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;
    --space-32: 8rem;

    /* Section Spacing */
    --section-spacing: clamp(4rem, 8vw, 8rem);
    --section-spacing-lg: clamp(6rem, 12vw, 12rem);

    /* Container */
    --container-max: 1280px;
    --container-narrow: 960px;
    --container-padding: clamp(1rem, 5vw, 2rem);

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --shadow-2xl: 0 25px 50px -12px rgb(0 0 0 / 0.25);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
    --transition-slower: 500ms ease;

    /* Z-Index Scale */
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal-backdrop: 400;
    --z-modal: 500;
    --z-tooltip: 600;

    /* Header */
    --header-height: 80px;
}

/* ===================================
   CSS Reset
   =================================== */
*,
*::before,
*::after {
    box-sizing: border-box;
}

* {
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-body);
    font-size: var(--text-base);
    font-weight: var(--font-normal);
    line-height: var(--leading-normal);
    color: var(--color-gray-800);
    background-color: var(--color-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img,
picture,
video,
canvas,
svg {
    display: block;
    max-width: 100%;
}

input,
button,
textarea,
select {
    font: inherit;
}

p,
h1,
h2,
h3,
h4,
h5,
h6 {
    overflow-wrap: break-word;
}

a {
    color: inherit;
    text-decoration: none;
}

ul,
ol {
    list-style: none;
}

button {
    background: none;
    border: none;
    cursor: pointer;
}

/* ===================================
   Typography
   =================================== */
.font-display {
    font-family: var(--font-display);
}

h1, h2, h3, h4, h5, h6,
.h1, .h2, .h3, .h4, .h5, .h6 {
    font-family: var(--font-display);
    font-weight: normal;
    font-feature-settings: "calt" 1;
    line-height: var(--leading-tight);
    color: var(--color-gray-900);
}

h1, .h1 {
    font-size: var(--text-5xl);
    letter-spacing: var(--tracking-tighter);
}

h2, .h2 {
    font-size: var(--text-4xl);
    letter-spacing: var(--tracking-tight);
}

h3, .h3 {
    font-size: var(--text-3xl);
}

h4, .h4 {
    font-size: var(--text-2xl);
}

h5, .h5 {
    font-size: var(--text-xl);
}

h6, .h6 {
    font-size: var(--text-lg);
}

p {
    margin-bottom: var(--space-4);
}

p:last-child {
    margin-bottom: 0;
}

.lead {
    font-size: var(--text-xl);
    line-height: var(--leading-relaxed);
    color: var(--color-gray-600);
}

.text-sm {
    font-size: var(--text-sm);
}

.text-lg {
    font-size: var(--text-lg);
}

.text-center {
    text-align: center;
}

/* ===================================
   Layout Utilities
   =================================== */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin-inline: auto;
    padding-inline: var(--container-padding);
}

.container--narrow {
    max-width: var(--container-narrow);
}

.section {
    padding-block: var(--section-spacing);
}

.section--lg {
    padding-block: var(--section-spacing-lg);
}

/* Flexbox */
.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

.items-center {
    align-items: center;
}

.items-start {
    align-items: flex-start;
}

.justify-center {
    justify-content: center;
}

.justify-between {
    justify-content: space-between;
}

.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

/* Grid */
.grid {
    display: grid;
}

.grid-cols-2 {
    grid-template-columns: repeat(2, 1fr);
}

.grid-cols-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-cols-4 {
    grid-template-columns: repeat(4, 1fr);
}

/* ===================================
   Color Utilities
   =================================== */
.text-primary { color: var(--color-primary); }
.text-primary-dark { color: var(--color-primary-dark); }
.text-accent { color: var(--color-accent); }
.text-warmth { color: var(--color-warmth); }
.text-white { color: var(--color-white); }
.text-gray-500 { color: var(--color-gray-500); }
.text-gray-600 { color: var(--color-gray-600); }

.bg-primary { background-color: var(--color-primary); }
.bg-primary-pale { background-color: var(--color-primary-pale); }
.bg-accent-pale { background-color: var(--color-accent-pale); }
.bg-gray-50 { background-color: var(--color-gray-50); }
.bg-white { background-color: var(--color-white); }

/* ===================================
   Spacing Utilities
   =================================== */
.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mt-12 { margin-top: var(--space-12); }

.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }
.mb-12 { margin-bottom: var(--space-12); }

/* ===================================
   Accessibility
   =================================== */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

/* Focus styles */
:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Skip link */
.skip-link {
    position: absolute;
    top: -100%;
    left: 50%;
    transform: translateX(-50%);
    padding: var(--space-3) var(--space-6);
    background: var(--color-primary);
    color: var(--color-white);
    border-radius: var(--radius-md);
    z-index: var(--z-tooltip);
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: var(--space-4);
}